Black iron oxide for use with cosmetics, production method thereof, and cosmetic materials comprising the same

ABSTRACT

To solve the problem of providing a black iron oxide that can yield sufficient blackness, opacifying effect and covering ability even if it is only added in a small amount for use with cosmetic materials, the invention provides a black iron oxide with a high tinting strength having an octahedral shape, a specific surface in a range of 8.0 to 20.0 m2/g, and a particle surface coated with a layer containing one type or two or more types of inorganic compounds, wherein an L* value of a colour on reduction is 31.0 or lower and a b* value of a colour on reduction is 1.5 or lower, a production method thereof, and cosmetic materials that incorporate the same.

TECHNICAL FIELD

The present invention relates to a black iron oxide for cosmetics with ahigh tinting strength, a production method thereof, and a cosmeticmaterial comprising black iron oxide.

BACKGROUND ART

Conventionally, black pigments are used in cosmetics for makeup ofspecific parts such as eyeliners. Those black pigments used forcosmetics which are commonly known are carbon black, black iron oxide,and titanium black, etc. Of these black pigments, carbon black andtitanium black are approved as coloring materials in some countries, butnot in others, and their use as materials for cosmetics in the globalmarket are largely limited.

On the other hand, black iron oxide is safe, and it is used globally asa black pigment for cosmetics, but its tinting strength is lower thanthat of carbon black, and a large amount must be added to the cosmeticsto obtain sufficient blackness, so it does not provide much degree offreedom in the recipe. Attempts are made to improve the tinting strengthof black iron oxide to solve this problem.

One way of improving the tinting strength of black iron oxide is toreduce the grain size. One method that has been presented for reducingparticle size is a method of forming bubbles of inert gas in an aqueoussolution containing ferrous ion to reduce the dissolved oxygen contentin the aqueous solution, then, adding an alkaline material to generateferrous hydroxide, heating the solution to a range of 60 to 100° C., andproducing a magnetite microcrystal (triiron tetroxide) having a particlesize of 0.01 to 0.1 μm (Patent Document 1). However, a decrease in thegrain size increases the surface area. As a result, there will be ahigher possibility of oxidation of the surface of black iron oxide whencontacting air at a high temperature, which leads to generation ofmaghemite that gives a reddish color. Patent Document 1 teaches that theblack iron oxide needs to be vacuum dried to obtain a fine black ironoxide, but when drying is performed industrially under air, theparticles turn brown. Hence, it is not practical to use black iron oxideas a black pigment for cosmetics.

In a conventional production of black iron oxide, a problem of colorchange by heat is experienced in the drying step during production, anda problem in heat resistance, such as thermochromism, is experiencedduring use. A production method has been proposed for producingmagnetite particle powder for black pigments by adding a ferrous saltsolution to an alkali hydroxide solution, passing oxidative gas over itat 80 to 100° C. and adding an aluminum compound, then subjecting theobtained magnetite particles to filtration, washing, drying, burning andpulverizing (Patent Document 2). The magnetite particles obtained byaddition of aluminum taught in Patent Document 2 has an octahedralshape, their average particle size is 0.1 to 0.2 μm, and the specificsurface is 20 m²/g to 50 m²/g, but the tinting strength of the particlesis not sufficient as black pigment. In Comparative Example 1, in whichaluminum is not added, the specific surface was 11.3 m²/g, but the colorturned reddish brown, and black pigment was not obtained.

A proposal has also been made of a black iron tetroxide having aparticle size of 100 nm or lower and a specific surface of 40 m²/g orhigher, which is obtained by dropping a water-soluble ferrous saltsolution into an alkali hydroxide or an alkali carbonate solution,blowing air into the solution to obtain a fine goethite precipitate(iron(II) oxyhydroxide), and hydrogenising the goethite precipitate at250 to 350° C. (Patent Document 3). The black iron tetroxide of PatentDocument 3 takes the form of needle shaped particles that do not easilydisperse, and are lacking in tinting strength.

CITATION LIST Patent Documents

[Patent Document 1] Japanese patent publication No. H04-238819

[Patent Document 2] Japanese patent publication No. 2000-327336

[Patent Document 3] Japanese patent publication No. S57-200230

SUMMARY OF INVENTION Technical Problem

The object of the present invention is to provide a black iron oxidewith a high tinting strength that can yield sufficient blackness,opacifying effect and covering ability even if it is only added in asmall amount for use with cosmetic materials, a production methodthereof, and cosmetic materials that incorporate a black iron oxide witha high tinting strength.

Solution to Problem

The present inventors performed extensive studies to develop a blackiron oxide with a high tinting strength that can yield sufficientblackness, opacifying effect and covering ability even if it is onlyadded in a small amount for use with cosmetic materials, and found thatcosmetic materials incorporating the black iron oxide with a hightinting strength having an octahedral shape, a specific surface in arange of 8.0 to 20.0 m²/g, a particle surface coated with a layercontaining one type or two or more types of inorganic compounds, andhaving a tinting strength indicated by an L* value of a colour onreduction of 31.0 or lower and a high blackness indicated by a b* valueof a colour on reduction of 1.5 or lower, yields sufficient blackness,opacifying effect and covering ability even if it is only added in asmall amount, wherein the L* value of a colour on reduction and the b*value of a colour on reduction are measured using a coated film made ofa reduction paste comprising the black iron oxide particles of thepresent invention. The present invention was thus completed.

The black iron oxide of the present invention has an octahedral particleshape. The black iron oxide can also take the shape of a cube, anedgeless cube or a sphere, other than the octahedron, but the octahedronhas the strongest tinting strength among those shapes. It is not clearwhy the tinting strength changes by the particle shape, but it isassumed that the good crystallinity of octahedron imparts a high lightabsorption efficiency and enhances the tinting strength. Further, goodcrystallinity causes improvement in heat resistance.

The index of the particle size of the black iron oxide of the presentinvention shown by the specific surface is in the range of 8.0 to 20.0m²/g. A black iron oxide having a high tinting strength indicated by anL* value of a colour on reduction that is 31.0 or lower cannot beobtained when the specific surface is lower than 8.0 m²/g. Further, aspecific surface that is higher than 20.0 m²/g causes the b* value ofthe colour on reduction to be higher than 1.5, and thus makes thebrownish color become more visible while blackness declines.

The particle surface of the black iron oxide of the present invention iscoated with a layer containing one type or two or more types ofinorganic compounds. An increase of the specific surface makes the blackiron oxide more susceptible to oxidation, and imparts a brownish colortone to the particles while reducing blackness, but when the particlesurface is coated with a layer containing one type or two or more typesof inorganic compounds, the coating blocks the contact with oxygen inair and regulates oxidation in the drying step, so the brownish color issuppressed and the reduction of blackness is regulated. The inorganiccompounds to coat the surface of the black iron oxide of the presentinvention may include hydroxides or oxides of metals, such as aluminum,silicon, zinc, titanium, zirconium, cerium and tin.

Advantageous Effects of Invention

The black iron oxide with a high tinting strength of the presentinvention has a higher tinting strength compared to conventional blackiron oxides, so it can yield sufficient blackness, opacifying effect andcovering ability even if it is only added in a small amount for use withcosmetic materials.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a scanning electron microscope (SEM) image showing theparticle shape of the black iron oxide with a high tinting strengthobtained in Example 1.

FIG. 2 is a SEM image showing the particle shape of the black iron oxideobtained in Comparative Example 1.

FIG. 3 is a SEM image showing the particle shape of a major black ironoxide, BL-100P (product of Titan Kogyo, Ltd.).

DESCRIPTION OF EMBODIMENTS

Detailed explanation is provided below of the black iron oxide with ahigh tinting strength of the present invention, a production methodthereof, and cosmetic materials incorporating said black iron oxide.

The present invention relates to a black iron oxide with a high tintingstrength having an octahedral shape, a specific surface in a range of8.0 to 20.0 m²/g, and a particle surface coated with a layer containingone type or two or more types of inorganic compounds, wherein an L*value of a colour on reduction is 31.0 or lower and a b* value of acolour on reduction is 1.5 or lower, a production method thereof, andcosmetic materials incorporating said iron oxide pigment. The particleshape of the black iron oxide of the present invention is the shapeobserved by a scanning electron microscope (SEM) image. As shown in FIG.1, the particle shape of the black iron oxide of the present inventionis a clear octahedral shape.

The specific surface of the black iron oxide of the present invention isa value measured by the single point BET method using Gemini 2360 (aproduct of Micromeritics) after deaeration of the sample in nitrogen at150° C. for 30 minutes.

An L* value of the colour on reduction and a b* value of the colour onreduction of the black iron oxide of the present invention are colorindices (L* value and b* value) shown according JIS Z 8781-4 based onvalues obtained by stirring 0.125 g of the sample, 0.375 g of titaniumdioxide and 1.0 ml of styresol with a hoover muller to form a paste,adding 2.0 ml of styresol to the paste, then mulling and forming a paintfrom the mixture, coating a cast coat paper with the mixture using a 150μm (6 mil) applicator to form a coated fragment (thickness of the film:about 30 μm), and air drying the fragment, followed by baking at 130° C.for 30 minutes, then measuring the color using a SM-7 type color testerby Suga Test Instruments. In addition, the “colour on reduction” is thataccording to the definition of the tinting strength of a pigment in JISK5101-3-1 (Test methods for pigments—Part 3: Tinting strength—Section 1:Determination of relative tinting strength and colour on reduction ofcoloured pigments—Visual comparison method). Namely, “colour onreduction” means colour of reduction of a coated film made of areduction paste, and “reduction paste” means paste obtained by mixingwhite pigment paste with colored pigment dispersed in a binder. In thepresent invention, the black iron oxide of the present inventioncorresponds to “colored pigment”

The L* value of the colour on reduction is an index of the tintingstrength, and the smaller the L* value of the colour on reduction, thehigher the tinting strength. The L* value of the colour on reduction ofthe conventional black iron oxide for cosmetics is about 38. An L* valueof the colour on reduction of 31.0 or lower provides a sufficiently hightinting strength.

The b* value of the colour on reduction is an index of blackness, and ahigher b* value of the colour on reduction makes the brownish color morevisible and reduces blackness. When the b* value of the colour onreduction exceeds 1.5, the brownish color becomes too strong to becalled black. When the b* value of the colour on reduction becomes anegative value, the blue color becomes strong, but a bluish black isalso included in the scope of the present invention.

<Production Method of Black Iron Oxide With High Tinting Strength>

The production method of black iron oxide with a high tinting strengthof the present invention is described in detail.

The ferrous salt solution was set to a predetermined temperature in theinert gas atmosphere, and an alkali solution at a neutralizationequivalent or higher was added to the solution to generate a ferroushydroxide slurry. Then, a predetermined amount of ferric salt solutionis added to the ferrous hydroxide slurry to induce nucleation of blackiron oxide. Subsequently, an alkali solution is added to the slurrycontaining nuclei of black iron oxide to adjust the pH of the slurry toa range of 12.0 to 13.0, and preferably, an oxygen-containing gas ispassed over the slurry while it is heated to a range of 60 to 100° C. toinduce the growth of the nucleus of black iron oxide. A predeterminedamount of metal salt is added to the slurry after generation of blackiron oxide has ended, and the pH of the mixture is adjusted by acid oralkali to obtain an insoluble hydroxide of the metal salt to bedeposited onto the particle surface of the black iron oxide. Then, theslurry containing black iron oxide coated with an inorganic compound isfiltered out, washed to remove salt impurities, and subsequently driedto obtain black iron oxide particles coated with an inorganic compound,preferably an inorganic metal hydroxide or oxide, of the presentinvention.

The ferrous salts used in the present invention include ferrouschloride, ferrous sulfate, and ferrous nitrate. In addition, hydroxidessuch as sodium hydroxide, potassium hydroxide, and ammonium hydroxide,carbonates such as sodium carbonate, potassium carbonate, and ammoniumcarbonate, or ammonia gas can be used as the alkali source, but analkali source that contains ammonia vaporizes at a high neutralizationtemperature, so hydroxides are preferable.

The ferric salt that can be used in the present invention includesferric chloride, ferric sulfate, and ferric nitrate. The amount offerric salt to be added is 0.8 to 5.0 wt % as Fe³⁺ against 100 wt % ofFe²⁺. When the amount of ferric salt to be added is too small, thespecific surface of the black iron oxide becomes smaller than 8.0 m²/g.On the other hand, when the amount of ferric salt to be added is toolarge, the specific surface becomes higher than 20.0 m²/g.

When the pH of the slurry containing nucleus of black iron oxide islower than 12.0, the black iron oxides will not grow sufficiently, andparticles having an octahedral shape will not be formed. An octahedralshape is also obtained when the slurry pH is higher than 13.0, but suchcase requires more alkali to be used and is not economic. When thetemperature for heating slurry containing nucleus of black iron oxide islower than 60° C., crystals of materials that are not black iron oxidesuch as goethite are generated, and the tinting strength and blacknessdeclines. The black iron oxide with a high tinting strength desired inthe present invention can be obtained at a temperature above 100° C.,but it is not economic.

The slurry after completing the generation of black iron oxide with ahigh tinting strength is coated with a layer of one type or two or moretypes of inorganic compounds on the particle surface to suppress thedecline of blackness due to oxidation in the drying step. Apredetermined amount of inorganic metal salt can be added to the slurrycontaining black iron oxide to transform the inorganic metal salt intoan insoluble hydroxide, and this process allows the surface of the blackiron oxide particle to be coated with an inorganic compound. Theinorganic metal salt to be used in the present invention is notparticularly limited as long as they can be formed into a hydroxide oroxide of metals, such as aluminum, silicon, zinc, titanium, zirconium,cerium and tin, but it is preferably sodium aluminate, aluminum sulfate,aluminum nitrate, aluminum chloride, sodium silicate, potassiumsilicate, silicon tetrachloride, zinc sulfate, zinc chloride, titaniumsulfate, titanium tetrachloride, zirconium oxychloride, zirconiumsulfate, zirconium nitrate, cerous chloride, cerium nitrate, ceriumacetate, tin chloride, stannous sulfate, and sodium stannate.

The amount of inorganic metal salt to be added is desirably an amountthat can form a coating of an inorganic compound, preferably a coatingof metal hydroxides or oxides in an amount of 0.5 to 5.0 wt % against100 wt % of black iron oxide. When the amount of inorganic compound tobe coated is lower than 0.5 wt %, the black iron oxide particle isoxidized in the drying step, the color tone becomes brownish, and thedecline in blackness cannot be regulated. When the amount of inorganiccompound for coating exceeds 5.0 wt %, the proportion of back iron oxidedecreases and the tinting strength decreases.

<Organic Surface Treatment>

The surface of the black metal oxide particles of the present inventioncan be made water repellent and/or oil repellent by an organic matter toimprove the dispersion stability and durability in the dispersion mediumin the production of cosmetics that incorporate the black iron oxideparticle of the present invention. The organic matter used herein mayinclude dimethylpolysiloxane, methylhydrogenpolysiloxane and othersilicone compounds, silane coupling agents, aluminum coupling agents,titanium coupling agents, zirconium coupling agents and other couplingagents, perfluoroalkyl phosphate compounds and other fluorine compounds,hydrocarbon, lecithin, amino acid, polyethylene, wax or lauric acid,stearic acid, isostearic acid and other fatty acids.

<Cosmetic Material>

The present invention provides a cosmetic material, in which black ironoxide particles that are surface coated with an inorganic compound(black iron oxide with a high tinting strength) are added in apredetermined amount against the main component of the cosmeticmaterial. The amount of black iron oxide with a high tinting strength tobe added in the cosmetic material may be set freely according to therequired characteristics of the various cosmetic materials, andpreferably in a range of 0.01-50 wt %, more preferably in a range of0.02-40 wt % against the cosmetic material.

<Inorganic Pigment and Organic Pigment That Can be Combined for Use>

The cosmetic material of the present invention can be combined for usewith various additive components used in common cosmetic materials, suchas inorganic pigments, and organic pigments. Inorganic pigments that canbe combined for use may include titanium oxide, zinc oxide, iron red,yellow iron oxide, ultramarine blue, iron blue, cerium oxide, talc,muscovite, synthetic mica, bronze mica, black mica, syntheticfluorphlogopite, titanium-mica, mica-like iron oxide, sericite, zeolite,kaoline, bentonite, clay, silica, silica anhydride, magnesium silicate,aluminum magnesium silicate, calcium silicate, barium sulfate, magnesiumsulfate, calcium sulfate, calcium carbonate, magnesium carbonate, boronnitride, bismuth oxychloride, alumina, zirconium oxide, magnesium oxide,chromium oxide, calamine, hydroxyapatite and composites thereof.Likewise, organic pigments that can be combined for use include siliconepowder, silicone elastic powder, polyurethane powder, cellulose powder,nylon powder, urethane powder, silk powder, PMMA powder, starch,polyethylene powder, polystyrene powder, tar dye, natural dye, metalsoaps, such as zinc stearate and composites thereof.

<Components That Can be Added>

Note that the cosmetic material of the present invention can incorporatecomponents other than those above in quantitative and qualitative rangesthat do not impair the effect of the present invention in view of thepurpose of use. For example, oil-based components, dyes, pH adjustors,humectants, thickeners, surfactants, dispersants, stabilizers,colorants, preservatives, antioxidants, sequestering agents,astringents, extinguishing agents, UV absorbers, perfumes and the likecan be added in a range that achieves the object of the presentinvention.

<Form of Cosmetic Materials>

The cosmetic material of the present invention can be produced by aknown method, and it can be in any form including powder, solid powder,cream, emulsion, lotion, liquid oil, solid oil, paste. For example, itcan be in the form of cosmetics for make-up, cosmetics for skin care,cosmetics for hair care and the like including makeup base, foundation,concealer, face powder, control color (makeup base), sun screen,lipstick, lip cream, eyeshadow, eye liner, mascara, cheek color,manicure, body powder, perfume powder, baby powder, solid soap, bathpowder, peel-off mask, without being limited thereby.

EXAMPLES

The present invention is described in more detail by Examples shownbelow. The following examples are given merely to provide examples, andthey do not limit the scope of the invention.

Production Example 1

A ferrous sulfate solution (2.15 L) containing 1.50 mol/L of Fe²⁺ wasadded to a 1.67 mol/L NaOH solution (3.85 L) in an inert gas atmosphereto generate ferrous hydroxide. (The amount of sodium hydroxide to beused is 1.04 equivalent against Fe²⁺.) Then, a ferric sulfate solutionat 1.7 wt % as Fe³⁺ against Fe²⁺ was added to the aqueous solutioncontaining ferrous hydroxide to generate a crystal nucleus of black ironoxide. Subsequently, a NaOH solution was added to a ferrous hydroxideslurry containing nucleus of black iron oxide to adjust the pH to 12.3.The ferrous hydroxide slurry containing the nucleus was mechanicallystirred at 90° C., then 2 L/min. of air was passed over for 120 minutesto induce growth of black iron oxide particles. Next, sodium aluminateat 1.5 wt % as Al₂O₃ was added slowly to the obtained black iron oxidewhile the mixture was stirred, and after 1 hour of stirring, dilutedsulfuric acid was added to adjust the pH to 8.0. The mixture wasfiltered and washed, then dried at 100° C. to obtain Sample A. Thescanning electron microscope (SEM) image of Sample A is shown in FIG. 1.As shown in FIG. 1, the particle shape of the obtained Sample A is anoctahedron. The specific surface of Sample A measured by the BET methodwas 13.3 m²/g. Further, the L* value of the colour on reduction ofSample A is 27.4, and the b* value of the colour on reduction is −1.1.

Production Example 2

A ferrous sulfate solution (2.15 L) containing 1.50 mol/L of Fe²⁺ wasadded to a 1.67 mol/L NaOH solution (3.85 L) in an inert gas atmosphereto generate ferrous hydroxide. (The amount of sodium hydroxide to beused is 1.04 equivalent against Fe²⁺.) Then, a ferric sulfate solutionat 4.2 wt % as Fe³⁺ against Fe²⁺ was added to the aqueous solutioncontaining ferrous hydroxide to induce nucleation of black iron oxide.Subsequently, a NaOH solution was added to a ferrous hydroxide slurrycontaining nucleus of black iron oxide to adjust the pH to 12.5. Theferrous hydroxide slurry containing the nucleus was mechanically stirredat 85° C., then 2 L/min. of air was passed over for 120 minutes toinduce growth of black iron oxide particles. Next, sodium aluminate at3.0 wt % as Al₂O₃ was added to the obtained black iron oxide slowlywhile the mixture was stirred, and after 1 hour of stirring, dilutedsulfuric acid was added to adjust the pH to 8.0. The mixture wasfiltered and washed, then dried at 100° C. to obtain Sample B. Theparticle shape of the obtained Sample B is an octahedron, and thespecific surface of Sample B measured by the BET method was 18.8 m²/g.Further, the L* value of the colour on reduction of Sample B was 27.7,and the b* value of the colour on reduction was 1.1.

Production Example 3

A ferrous sulfate solution (2.15 L) containing 1.50 mol/L of Fe²⁺ wasadded to a 1.67 mol/L NaOH solution (3.85 L) in an inert gas atmosphereto generate ferrous hydroxide. (The amount of sodium hydroxide to beused is 1.04 equivalent against Fe²⁺.) Then, a ferric chloride solutionat 0.9 wt % as Fe³⁺ against Fe²⁺ was added to the aqueous solutioncontaining ferrous hydroxide to induce nucleation of black iron oxide.Subsequently, a NaOH solution was added to a ferrous hydroxide slurrycontaining nucleus of black iron oxide to adjust the pH to 12.1. Theferrous hydroxide slurry containing the nucleus was mechanically stirredat 95° C., then 2 L/min. of air was passed over for 120 minutes toinduce growth of black iron oxide particles. Next, sodium aluminate at1.5 wt % as Al₂O₃ was added slowly to the obtained black iron oxidewhile the mixture was stirred, and after 1 hour of stirring, dilutedsulfuric acid was added to adjust the pH to 8.0. The mixture wasfiltered and washed, then dried at 100° C. to obtain Sample C. Theparticle shape of Sample C is an octahedron, and the specific surface ofSample C measured by the BET method was 8.6 m²/g. Further, the L* valueof the colour on reduction of Sample C was 28.8, and the b* value of thecolour on reduction was −2.9.

Production Example 4

A ferrous sulfate solution (2.15 L) containing 1.50 mol/L of Fe²⁺ wasadded to a 1.67 mol/L NaOH solution (3.85 L) in an inert gas atmosphereto generate ferrous hydroxide. (The amount of sodium hydroxide to beused is 1.04 equivalent against Fe²⁺.) Then, a ferric sulfate solutionat 1.7 wt % as Fe³⁺ against Fe²⁺ was added to the aqueous solutioncontaining ferrous hydroxide to induce nucleation of black iron oxide.Subsequently, a NaOH solution was added to a ferrous hydroxide slurrycontaining nucleus of black iron oxide to adjust the pH to 12.7. Theferrous hydroxide slurry containing the nuclei was mechanically stirredat 80° C., then 2 L/min. of air was passed over for 120 minutes toinduce growth of black iron oxide particles. Next, sodium silicate at3.0 wt % as SiO₂ was added slowly to the obtained black iron oxide whilethe mixture was stirred, and after 1 hour of stirring, diluted sulfuricacid was added to adjust the pH to 5.0. The mixture was filtered andwashed, then dried at 100° C. to obtain Sample D. The particle shape ofthe obtained Sample D is an octahedron, and the specific surface ofSample D measured by the BET method was 13.0 m²/g. Further, the L* valueof the colour on reduction of Sample D was 27.5, and the b* value of thecolour on reduction was −1.0.

Production Comparative Example 1

A process similar to Production Example 1, other than that the pH afternucleation was adjusted to 8.8, was performed to obtain Sample E. Thescanning electron microscope (SEM) image of Sample E is shown in FIG. 2.As shown in FIG. 2, the particle shape is a sphere. The specific surfaceof Sample E was 12.0 m²/g. Further, the L* value of the colour onreduction of Sample E was 31.5, and the b* value of the colour onreduction was −1.6.

Production Comparative Example 2

A process similar to Production Example 1, other than that a ferricsulfate solution was added at an amount of 0.7 wt % as Fe³⁺ againstFe²⁺, was performed to obtain Sample F. The particle shape of Sample Fwas an octahedron, and the specific surface was 7.5 m²/g. Further, theL* value of the colour on reduction of Sample F was 31.7, and the b*value of the colour on reduction was −3.4.

Production Comparative Example 3

A process similar to Production Example 1, other than adding a ferricsulfate solution at an amount of 7.0 wt % as Fe³⁺ against Fe²⁺, wasperformed to obtain Sample G. The particle shape of Sample G was anoctahedron, and the specific surface was 22.0 m²/g. Further, the L*value of the colour on reduction of Sample G was 27.5, and the b* valueof the colour on reduction was 2.4.

Production Comparative Example 4

A process similar to Production Example 1, other than that no surfacetreatment was performed after generating black iron oxide (addition ofsodium aluminate), was performed to obtain Sample H. The particle shapeof Sample H was an octahedron, and the specific surface was 13.1 m²/g.Further, the L* value of the colour on reduction of Sample H was 28.9,and the b* value of the colour on reduction was 1.7.

Examples 1-4, Comparative Examples 1-5 Pressed Eyeshadows

20.0 wt % of either of Samples A-D obtained in Production Examples 1-4and Samples E-H obtained in Production Comparative Examples 1-5, andBL-100P produced by Titan Kogyo, Ltd. shown in the picture of FIG. 3 asa typical black iron oxide (particle shape: edgeless cube, specificsurface 6.6 m²/g, L* value of the colour on reduction: 39.0, b* value ofthe colour on reduction: −4.2), 35.0 wt % of sericite, 14.9 wt % oftalc, 20.0 wt % of titanium-mica (produced by BASF: Flamenco Super Pearl120C) and 0.1 wt % of methylparaben were mixed/ground, and mixed. Then,7.0 wt % of dimeticone 1000 cs (viscosity of 1000 mm²/s) and 3.0 wt % ofdiisostearyl malate that were mixed in a different container were addedand stirred/mixed to homogenize the mixture. The mixture was dispersedin isopropyl alcohol to achieve a suitable viscosity, and pressed/filledin a gold plate having a diameter of 57 mm and a depth of 4 mm using aslurry filler. Then the mixture was dried at 40° C. for 12 hours toobtain the desired pressed eyeshadow.

[Assessment Items and Assessment Method Using Black Iron Oxide With aHigh Tinting Strength]

<Sensory Assessment>

The obtained pressed eyeshadow was subjected to a sensory assessmentconcerning the covering ability, blackness, gloss and the like.

<Assessment and Assessment Standard>

The pressed eyeshadows created in Examples 1-4 and Comparative Examples1-5 were tested on 10 panels; a sensory assessment was performed byrating the sensory assessment items of Table 1 in a scale of 1 to 5; andthe average score was used for judgment.

<Assessment Standard>

-   Very good: 5 Good: 4 Acceptable: 3 Not good: 2 Bad: 1

<Judgment Standard>

-   4.0-5.0 points: ⊚ 3.0-lower than 4.0 points: ∘ 2.0-lower than 3.0    points: Δ 1.0-lower than 2.0 points: ×

The results are shown in Table 1.

TABLE 1 Comp. Comp. Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 1 Ex.2 Ex. 3 Ex. 4 Ex. 5 Applied black Sample A Sample B Sample C Sample DSample E Sample F Sample G Sample H BL- iron oxide 100P Test ItemsCovering ability ⊚ ⊚ ◯ ⊚ Δ Δ ⊚ ⊚ X Blackness ◯ ◯ ⊚ ◯ ◯ ⊚ X X ⊚ Gloss ⊚ ◯⊚ ⊚ X ◯ Δ Δ ◯

As a result of the sensory assessment, the pressed eyeshadows obtainedin Examples 1-5 of the present invention all had good covering abilityand blackness, as well as gloss, compared to Comparative Examples 1-4 orComparative Example 5, which incorporates a conventional black ironoxide. A cosmetic material that has good covering ability and blackness,and produces a glossy finish was obtained by incorporating a black ironoxide with high tinting strength having an octahedral shape, a specificsurface in a range of 8.0 to 20.0 m²/g, a particle surface coated with alayer containing one or two or more types of inorganic compounds, and anL* value (colour on reduction) of 31.0 or lower and a b* value (colouron reduction) of 1.5 or lower.

Example 5 Aqueous Eyeliner

TABLE 2 <Components> Weight (%) 1. Production Example 2 (Sample B) blackiron oxide 7.0 with high tinting strength 2. Purified water 21.5 3.Decaglyceryl laurate 1.0 4. Glycerine 6.0 5. Carboxymethyl cellulose 10%solution 18.0 6. Phenoxyethanol 0.5 7. Pentylene Glycol 1.0 8. Vinylacetate resin emulsion 45.0 (Nisshin Chemical Industry Co., Ltd.Vinyblan GV-5651)

<Production Method>

-   A: Components 1-3 were weighed out, and the black iron oxide was    finely dispersed using a bead mill.-   B: Components 4-7 were weighed out in a different container, and    after A was added at 70° C. to the components and the mixture was    dispersed homogenously, it was cooled to room temperature. Component    8 was added to obtain an aqueous eyeliner.

The obtained aqueous eyeliner had high blackness and opacifying effect.

Example 6 Emulsified Mascara

TABLE 3 Weight <Components> (%) 1. Purified water 23.1 2. Polyvinylpyrrolidone 2.0 3. Propanediol 2.0 4. Cationized cellulose 1% solution10.0 5. Bentonite 0.5 6. Triethanolamine 1.7 7. Methylparaben 0.2 8.Talc 4.0 9. Production Example 2 (Sample B) black iron oxide with a 10.0high tinting strength 10. Carnauba wax 5.5 11. Beeswax 9.0 12. Stearicacid 2.0 13. Self-emulsifiable glyceryl stearate 2.0 14. Propyleneglycol stearate 2.0 15. Hydrogenated polyisobutene 2.0 16.Cyclomethicone 4.0 17. Acrylate resin emulstion <Daito Kasei Kogyo 20.0Co. DAITOSOL 5000AD>

<Production Method>

-   A: Components 8-10 were stirred/mixed using a Henschel mixer.-   B: A was added to Components 1 to 7, and the mixture was dispersed    homogenously using a stirrer.-   C: After heated/dissolved Components 11-16 were added to B and    emulsified, the mixture was cooled to 40° C., Component 17 was    added, and the mixture was cooled to room temperature to obtain an    emulsified mascara.

The obtained emulsified mascara was an emulsified mascara with asomewhat reddish blackness and a good opacifying effect.

Example 7 Eyebrow Pencil

TABLE 4 <Components> Weight (%) 1. Production Example 4 (Sample D) blackiron oxide 20.0 with a high tinting strength 2. Titanium oxide 5.0 3.Talc 10.0 4. Kaoline 15.0 5. Japan wax 21.0 6. Stearic acid 10.0 7.Beeswax 5.0 8. Hydrogenated castor oil 5.0 9. Vaseline 3.0 10. Lanolin3.0 11. Squalane 3.0 12. Preservative suitable amount 13. Antioxidantsuitable amount

<Production Method>

-   A: Components 1 to 4 were mixed/ground.-   B: To heated/dissolved Components 5 to 13, A was added and the    mixture was homogenously kneaded using a three roll mill.-   C: The mixture was molded into a core and surrounded by wood into a    pencil shape to obtain an eyebrow pencil.

The obtained eyebrow pencil had a smooth use, since it not only had highblackness, but it could also be added in a smaller amount.

Example 8 Cheek

TABLE 5 <Components> Weight (%) 1. Triethoxycaprylylsilane-treated talc25.0 2. Triethoxycaprylylsilane-treated sericite 61.0 3. Stearic acidtreated titanium oxide particle (Titan 3.0 Kogyo, Ltd. STV-455) 4.Triethoxycaprylylsilane-treated titanium oxide 2.0 5. Black iron oxidewith a high tinting strength of 0.05 Production Example 1 (Sample A)treated with triethoxycaprylylsilane at an amount of 1.5 wt % 6.Triethoxycaprylylsilane-treated iron red 0.15 7.Triethoxycaprylylsilane-treated yellow iron oxide 0.8 8. Ethylhexylmethoxycinnamate 3.0 9. Ethylhexyl palmitate 5.0 10. Preservativesuitable amount 11. Antioxidant suitable amount

<Production Method>

-   A: Components 1-7 were mixed using a Henschel mixer.-   B: Components 8 to 11 were heated/dissolved and added to A, then it    was ground with an atomizer.-   C: The mixture was press-molded on an aluminum plate to obtain the    desired check.

The obtained cheek had good usability.

Example 9 Nail Enamel

TABLE 6 Weight <Components> (%) 1. Nitrocellulose (½ sec.) 10.0 2.Modified alkyd resin 10.0 3. Acetyl tributyl citrate 5.0 4. Ethylacetate 20.0 5. Ethanol 5.0 6. Toluene 34.0 7. Production Example 2(Sample B) black iron oxide with a 3.0 high tinting strength 8. Blackiron oxide-coated titanium-mica (Timica 10.0 Nu-Antique Silver by BASF)9. Organically modified montmorillonite 3.0

<Production Method>

-   A: A half amount of each of Components 2, 3 was collected, and they    were mixed with Components 7-8 and kneaded together.-   B: Residue of Components 2, 3 and Components 1, 4-6 and 9 were added    to A, and mixed until the mixture was homogenized to obtain nail    enamel.

The obtained nail enamel had good blackness and opacifying effect.

Example 10 O/W Emulsified Foundation

TABLE 7 <Components> Weight (%) 1. Stearic acid 1.0 2. Isostearic acid0.3 3. Ethyl hexanoic acid cetyl 4.0 4. Liquid paraffin 70cs 11.0 5.Steareth-10 2.0 6. Cetyl alcohol 1.5 7. Triethoxycaprylylsilane-treatedtalc 5.0 8. Black Iron oxide with a high tinting strength of 0.2Production Example 3 (Sample C) treated with Triethoxycaprylylsilane atan amount of 1.0 wt % 9. Triethoxycaprylylsilane-treated iron red 0.310. Triethoxycaprylylsilane-treated yellow iron oxide 1.8 11.Triethoxycaprylylsilane-treated titanium oxide 8.0 12. Triethanolamine1.2 13. Propanediol 5.0 14. Xanthan gum 0.2 15. Purified water 58.0 16.Phenoxyethanol 0.5

<Production Method>

-   A: Components 7 to 11 were mixed/ground.-   B: To Components 1 to 6 heated/dissolved at 85° C., A was added and    the mixture was dispersed homogenously.-   C: Components 12 to 16 were heated/dissolved at 85° C. and gradually    added to B to obtain an emulsified mixture, and the mixture was    stirred/cooled to room temperature to fill a suitable container and    to obtain an O/W emulsifying foundation.

The obtained O/W emulsifying foundation spreads well, and it has a goodcovering ability as well as a fresh feel.

Example 11 Two-Way Cake Foundation

TABLE 8 <Components> Weight (%) 1. Dimethicone-treated talc residue 2.Dimethicone-treated titanium oxide 10.0 3. Dimethicone-treated mica 20.04. Dimethicone-treated sericite 36.0 5. Nylon powder 10.0 6.Dimethicone-treated yellow iron oxide 1.0 7. Dimethicone-treated ironred 0.5 8. Black iron oxide with a high tinting strength of 0.1Production Example 4 (Sample D) treated with 1.0 wt % dimethicone 9.Dimethicone 1000cs 6.0 10. Isotridecyl isononanoate 3.0 11. Squalane 3.012. Tocopherol 0.1 13. 1,3-Butylene glycol 1.0

<Production Method>

-   A: Components 1-8 were mixed using a Henschel mixer.-   B: Components 9 to 13 were heated/dissolved and added to A.-   C: B was ground in an atomizer, and press-molded in an aluminum    plate to obtain a two-way foundation.

The obtained two-way foundation had a smooth feel, and a fresh feel.

Example 12 Lipstick

TABLE 9 Weight <Components> (%) 1. Ceresin 10.0 2. Microcrystalline wax3.2 3. Paraffin 5.0 4. Pentaerythrityl tetraisostearate 20.0 5.Diisostearyl malate 15.0 6. Hydrogenated polydecene 10.0 7. Vaseline10.0 8. Polyglyceryl Triisostearate-2 22.1 9. Simethicone 0.1 10.Propylparaben 0.1 11. Red 202 0.6 12. Production Example 1 (Sample A)black iron oxide with a 0.1 high tinting strength 13. Titanium oxide 0.414. Iron red 0.4 15. Titanium-Mica (BASF: Flamenco Sparkle Gold 220J)2.0 16. Silica 1.0

<Production Method>

-   A: Components 1-16 were weighed out, and heated/mixed.-   B: A was dispersed evenly using a three roll mill, then it was    further heated and stirred to a homogenous state.-   C: After defoaming, a bulk of A was poured into a mold, and    quenched. The bulk was fixed in a suitable container to obtain a    lipstick.

The obtained lipstick exhibited a deep red color, and showed a uniquecolor tone.

Example 13 Body Shampoo

TABLE 10 <Components> Weight (%) 1. Lauric acid 11.5 2. Myristic acid7.7 3. Palmitic acid 4.8 4. Potassium hydroxide (48%) 12.2 5. Laurylhydroxy sulfo betaine 10.0 6. Cocamide monoethanolamide 1.0 7. Ethyleneglycol distearate 2.0 8. Purified water 50.2 9. EDTA-4Na 0.1 10.Production Example 1 (Sample A) black iron oxide 0.1 with a high tintingstrength 11. Talc 0.4

<Production Method>

-   A: Components 1 to 3 were heated/dissolved at 70 to 80° C.-   B: Components 10 to 11 were mixed/ground.-   C: Component 4 was added gradually to A to perform saponification.    After saponification was completed, Components 5 to 9 were added,    and the mixture was stirred until it reached a homogenous state.-   D: C was cooled to 40° C., then B was added to it and the mixture    was cooled to room temperature while it was being stirred/mixed to    obtain a body shampoo.

The obtained body shampoo was colored with only a small amount ofpigments, so pigments were prevented from precipitating under a hightemperature environment.

Example 14 Solid Soap

TABLE 11 Weight <Components> (%) 1. Fatty acid alkali metal salt (lauricacid 38%, myristic acid 94.5 37%, palmitic acid 15%, stearic acid 10%)(potassium:sodium = 1:5) 2. Cocamidopropyl betaine 3.0 3. Glycerine 2.04. Production Example 2 (Sample B) black iron oxide with a 0.5 hightinting strength

<Production Method>

-   A: Sodium hydroxide (48%) and potassium hydroxide (48%) were added    to a fatty acid of a composition of Component 1, then the mixture    was stirred/mixed at a high temperature to prepare a fatty acid    alkali metal salt of Component 1.-   B: Components 2 to 4 were added to A, and mixed together, then the    mixture was homogenized using a three roll mill.-   C: B was kneaded/pressurized and extruded into a stick soap with an    extruder, then molded with a stamping machine to obtain a solid    soap.

The obtained solid soap had a water content of 11.5%, and it had astable blackness and somewhat of a red tint.

Example 15 Bath Powder

TABLE 12 Weight <Components> (%) 1. Sodium sulfate 86.0 2. Sodiumhydrogen carbonate residue 3. Sodium glutamate 2.0 4. Silica (AGCSi-Tech Co., Ltd. SUNSPHERE H-52) 1.0 5. Production Example 1 (Sample A)black iron oxide with a 0.5 high tinting strength 6. Vanillylbutyl ether0.2 7. Capsicum extract 0.1

<Production Method>

Components 1 to 7 were weighed out and mixed evenly using a Henschelmixer to obtain a bath powder.

A use of the obtained bath powder made the warm water in the bath tubturn a translucent black color.

Example 16 Peel-Off Mask

TABLE 13 Weight <Components> (%) 1. PEG1500 8.0 2. PEG/PPG-25/30copolymer 6.0 3. Xanthan gum 0.2 4. Sodium citrate 0.3 5. Citric acid0.1 6. Purified water 49.0 7. Polyvinyl alcohol 10.0 8. Polysorbate-800.2 9. Silica (AGC Si-Tech Co., Ltd. SUNSPHERE H-51) 4.0 10. Talc 8.011. Production Example 1 (Sample A) black iron oxide with a 1.0 hightinting strength 12. Alkyl acrylate copolymer emulsion 5.0 13.Methylparaben 0.2 14. Ethanol 8.0

<Production Method>

-   A: Components 9 to 11 were mixed/ground.-   B: To heated/dissolved Components 1 to 8, A was added and evenly    dispersed, then, the mixture was cooled to 40° C.-   C: Components 12 to 14 were added to B, then stirred/cooled to room    temperature to prepare a peel-off mask.

The obtained peel-off mask exhibited a homogenous black color, and itmade sebum and dirt visible after the mask was removed.

1-4. (canceled)
 5. A method, comprising: reacting a ferrous saltsolution with an alkali hydroxide to form a ferrous hydroxide slurry;adding a ferric salt solution to the ferrous hydroxide slurry to producea ferrous hydroxide slurry containing a nucleus of black iron oxide;adjusting a pH of the ferrous hydroxide slurry containing the nucleus ofblack iron oxide to 12.0 to 13.0; introducing an oxygen-containing gasover the ferrous hydroxide slurry containing the nucleus of black ironoxide and heating the slurry to grow the nucleus of black iron oxide andform a ferrous hydroxide slurry containing a black iron oxide particle;and adding an inorganic metal salt to the ferrous hydroxide slurrycontaining the black iron oxide particle to form a black iron oxideparticle having a layer containing an hydroxide or an oxide of theinorganic metal salt on a surface thereof having an octahedral shape anda specific surface area of 8.0 to 20.0 m²/g, wherein an L* value of acolour on reduction of the black iron oxide particle having a layercontaining an hydroxide or an oxide of the inorganic metal salt on asurface thereof according to JIS K5101-3-1 is 31.0 or lower and a b*value of a colour on reduction of the black iron oxide particle having alayer containing an hydroxide or an oxide of the inorganic metal salt ona surface thereof according to JIS K5101-3-1 is 1.5 or lower.
 6. Themethod according to claim 5, wherein the inorganic compound coated onthe surface of the black iron oxide particle is a hydroxide or an oxideof one or more of aluminum, silicon, zinc, titanium, zirconium, cerium,or tin.
 7. The method according to claim 5, further comprisingincorporating the black iron oxide particle having a layer containing anhydroxide or an oxide of the inorganic metal salt on a surface thereofinto a cosmetic material.
 8. The method according to claim 7, whereinthe cosmetic material is in the form of a makeup base, foundation,concealer, face powder, control color, sun screen, lipstick, lip cream,eye shadow, eye liner, mascara, cheek color, manicure, body powder,perfume powder, baby powder solid soap bath powder or peel-off mask. 0